Don't look at it. It doesn't work in 2.0.6, it works in 2.0.7, but even 2.0.7
has some buffer overrun problems if the end of the source or destination
happen to be at a page boundary (2.0.8 will work, or if you _really_ want to
go blind you can ask me for the patch).
You _really_ don't want to look at the csum+copy stuff. I'll be having
nightmares for weeks from having written the d*mn stuff..
Linus